Abstract: A light source unit includes: elemental light sources each including light emitting elements and drive circuits; an integrated control circuit that controls the drive circuits; and band optical characteristic acquisition sections that receive light of an amount correlated with a total light amount of output luminous fluxes to acquire light emitting intensity indicating values and wavelength deviation indicating values. The integrated control circuit at least intermittently acquires band optical characteristic acquisition data to generate the light emitting intensity indicating values and the wavelength deviation indicating values.

Abstract: Optical communication using optical resonators with noise margins is disclosed. A representative system includes an optical fiber for transmitting optical signals, a receiver configured to receive the optical signals, and a plurality of optical resonators optically connecting the optical fiber to the receiver. The individual optical resonators can have peak sensitivities at mutually different wavelengths of light. In some embodiments the optical resonators can be Q-switches.

Abstract: A light emitting apparatus includes: a semiconductor layer including a light emitting region that generates modulation light modulated with a first signal, and a feedback region that is configured so that a feedback mode to feed back a part of light generated in the light emitting region to the light emitting region and a monitor mode to monitor a light amount of the light generated in the light emitting region are switchable; and a controller, wherein when the modulation light is generated in the light emitting region, the controller sets the feedback region to the feedback mode, and the controller switches the feedback region to the monitor mode during at least a part of a period in which there is no first signal.

Abstract: An adaptive algorithm based battery-powered long distance wireless temperature and humidity sensor module. The sensor module uses an adaptive algorithm to transmit data on an event basis and/or a reduced basis to extend battery life to more than 10 years. It also uses a low power wireless transmitter which has frequency of sub-1 GHz and an effective transfer distance of up to 250 meters, a low power temperature and humidity sensor, and a long lasting lithium battery which has shelf life of 20 years.

Abstract: A method for making a light-emitting diode (LED) emitter module includes providing a substrate and providing two or more groups of LED dies disposed on the substrate. Each group has one or more LED dies, and each of the LED dies is coupled to an electrical contact and electrical paths are configured for feeding separate electrical currents to the groups of LED dies. The method also includes determining information associating a plurality output light colors with a corresponding plurality of combinations of electrical currents, each combination specifying a plurality of electrical current values, each electrical current value being associated with an LED die from one of the two or more groups of LED dies. The method also includes storing the information in the memory device, and providing a circuit for accessing the information in the memory device.

Abstract: A robot system includes a robot linkage (202) having one or more arms connected by two joints (220, 222). The joints each including a joint axis of rotation (206 or 208) and a light source (128) aligned with the respective joint axis. The light sources are configured to direct light along the respective joint axis such that light from the light sources intersects at a position along an instrument (204) being held in an operational position by the robot linkage to define a remote center of motion (RCM) for the robot linkage.

Abstract: Embodiments of the invention include an apparatus including an enclosure configured to receive an endoscope having an electromagnetic radiation sensor. The apparatus also includes an electromagnetic radiation source having at least a portion disposed within the enclosure. The electromagnetic radiation source is configured to emit electromagnetic radiation based on a calibration instruction. The electromagnetic radiation sensor is configured to receive at least a portion of the electromagnetic radiation when at least a portion of the endoscope is coupled to the enclosure.

Abstract: A light beam scanning device includes a lens element assembly which dynamically adjusts a divergence of the beam. The lens element assembly can include multiple lens elements, one or more of which translates parallel to the light beam to adjust beam divergence. Divergence adjustment can include adjusting the beam divergence along one or more cross sectional axes of the beam. Beam divergence can be adjusted between consecutive scans, during a scan, etc. Beam divergence can be adjusted based on the field of view and scan rate. Beam divergence adjustment can enable dynamic adjustment of the spot size of the beam, which can enable the apparatus to adjust between scanning a wide divergence beam to detect objects in a scene and scanning a narrow divergence beam to generate detailed point clouds of the detected objects. Beam divergence adjustment can enable adjustment of reflection point intensity, enabling detection of low-reflectivity objects.

Abstract: A tooth-whitening process includes providing an array of LEDs disposed in a first plane and forming an inner arc having an inner focal point and an outer arc having an outer focal different from the inner focal point; applying a whitening composition to at least the anterior surfaces of at least six mandibular or maxillary anterior teeth and maintaining the whitening composition on the at least six teeth for a first time period; after the first time period, directing a light radiation comprising blue visible light or near-visible UV light of at least a threshold intensity from the least a first array of LEDs for a second time period to the anterior surfaces of the at least six teeth, the first time period having a duration greater than 50% of a total duration of the first time period and the second time period; and removing the whitening composition from the at least six teeth.

Abstract: A method controls a light barrier where light is emitted from an optical transmitter to an optical receiver. The method checks whether reception levels fall below a lower threshold or exceed an upper threshold to determine whether the light barrier is interrupted. The thresholds initially are adjusted based on a predetermined minimum reception level, with each threshold being a fraction of the minimum reception level. An allowable reception level range is defined between the minimum level and a predetermined saturation level. The method checks whether the current reception level is outside the allowable reception level range, and, if this is the case, calibrates a parameter for operating the optical transmitter based on the minimum reception level and/or the saturation reception level. The parameter is calibrated by calculating a gradient of one characteristic curve of the light barrier and readjusting the parameter to a target value calculated based on the gradient.

Abstract: Provided is a sensor system for an outdoor lighting system including at least one sensor physically connected with an external connector of a lighting fixture of the outdoor lighting system. The sensor performs sensing and wireless data and power connection, via a wireless power source and a wireless data source, with the outdoor lighting system.

Abstract: Various embodiments relate to systems and methods for controlling one or more LED-based lighting sources that are coupled to a logic module by a ribbon cable. The ribbon cable allows some or all of the processing components (e.g., processors and drivers) to be decoupled from the LED-based lighting source(s). The processing components can instead be housed within the logic module, which is able to simultaneously control the LED-based lighting source(s). Together with color models established for each LED board, the logic module acts as a platform for modularity and is able to more precisely control the color channels of each LED-based lighting source using the color models established for those LED-based lighting source(s). Techniques are also described herein that allow the logic module to utilize data stored within an erasable programmable read-only memory (EPROM) that describes the color characteristics of an LED-based lighting source.

Abstract: An extreme ultraviolet light generating system repetitively outputs extreme ultraviolet light emitted by a target that turns into plasma by being irradiated with a pulsed laser beam. The extreme ultraviolet light generating system may include: a target supply unit that sequentially supplies the target to a plasma generating region set within a chamber, an actuator connected to a laser beam focusing system that focuses the pulsed laser beam output from a laser apparatus that adjusts the focusing position of the pulsed laser beam, an extreme ultraviolet light generation controller that controls the extreme ultraviolet light generating system to output extreme ultraviolet light based on a burst pattern, and an actuator controller that controls the actuator to compensate for shifts of the focusing position of the pulsed laser beam during a burst operation by feedforward control.

Abstract: Embodiments of a novel control device and associated techniques for controlling a light path length of a resonator to allow resonance in a mode of higher strength are described herein. The control device includes: a drive section that moves at least one reflecting unit in the resonator; and a control section that controls a light path length of the resonator, by causing the drive section to move the at least one reflecting unit so that the laser light that enters into the resonator changes from a state in which the laser light resonates in a first mode of the plurality of modes to a state in which the laser light resonates in a second mode different from the first mode, on the basis of a detection result of a reflected light from the resonator.

Abstract: A communication device includes: a signal generator configured to generate a first signal and supply the first signal to a telephone line; a terminator having a variable terminal impedance as seen from the telephone line; a detector configured to detect a difference between the terminal impedance and a line impedance of the telephone line; and a controller configured to determine the terminal impedance so that the difference is reduced.

Abstract: Embodiments of the present disclosure provide a method and system for dynamically controlling a current that is applied to a light source of an optical encoder.

Abstract: A photoelectric sensor includes the following components. A disturbance detection unit detects a disturbance by comparing a light reception result obtained by a light receiver with a first threshold and with a second threshold for a predetermined period in a state where no light is transmitted by a light transmitter. The second threshold takes a value of a sign opposite to that of the first threshold relative to a no-signal state. A waiting unit waits for the light reception result obtained by the light receiver to become within a range from the first threshold to the second threshold upon detection of a disturbance. A disturbance type determination unit causes detection of a disturbance to be performed again after the waiting. A light transmission instruction unit instructs the light transmitter to transmit light when no disturbance is detected for a predetermined period.

Abstract: A bridge circuit arrangement, method of providing said bridge circuit arrangement, and uses thereof are described. The bridge circuit arrangement comprises a first photodevice configured on a first arm, a second photodevice configured on a second arm, a first resistor configured on a third, the first resistor being a variable resistor and a second resistor configured on a fourth arm of the bridge, the second resistor being a constant resistor. The first and second photodevice provide current flow in opposing directions. The first photodevice on the first arm includes a third resistor having an equivalent resistance to the first photodevice. The second photodevice on the second arm includes a fourth resistor having an equivalent resistance to the second photodevice. The bridge circuit arrangement is balanced by illuminating the first and second photodiode and adjusting the arrangement so the net current is zero.

Abstract: Methods and systems for performing three dimensional LIDAR measurements with different pulse repetition patterns are described herein. Each repetitive pattern is a sequence of measurement pulses that repeat over time. In one aspect, the repetition pattern of a pulsed beam of illumination light emitted from a LIDAR system is varied to reduce total energy consumption and heat generated by the LIDAR system. In some examples, the repetitive pattern is varied by skipping a number of pulses. In some examples, the repetitive pattern of pulses of illumination light emitted from the LIDAR system is varied by changing a repetition rate of the sequence of emitted pulses. In some examples, the pulse repetition pattern is varied based on the orientation of the LIDAR device. In some examples, the repetition pattern is varied based on an object detected by the LIDAR device or another imaging system.

Abstract: An electric apparatus includes an electric device that performs operation using electric power being supplied, a receiver that receives one or more control commands for controlling the electric device from a server through a network, a memory that stores control command history information including a content of one or more control commands that are previously received from the server, and circuitry that determines whether or not a control command is received from the server for a predetermined period of time, generates, if the control command is not received from the server for a predetermined period of time, other control command using the content stored in the control command history information, and controls, if the control command is not received from the server for the predetermined period of time, the electric device based on the other control command being generated.

Abstract: The present invention discloses a test device, a method of manufacturing the test device, and a display apparatus. The test device comprises a first test electrode and a second test electrode. The first test electrode is configured to electrically connect with an electrode layer of an array substrate, and the electrode layer is a gate electrode layer or a source-drain electrode layer. The second test electrode is configured to electrically connect with a first transparent conductive layer provided on the array substrate, and the first transparent conductive layer is electrically connected to a second transparent conductive layer provided on a color film substrate. Thereby, it is possible to test liquid crystal characteristics of the whole liquid crystal display panel by applying a DC voltage through the first test electrode and the second test electrode.

Abstract: The light source module may include a plurality of light-emitting units, at least two optical units, and at least two light conversion units. Light from a first light-emitting unit exits as first exiting light processed by a first and second optical units, light from a second light-emitting unit forms first converted light processed by the first optical unit and converted by a first light conversion unit, light from a third light-emitting unit forms second converted light processed by the second optical unit and converted by a second light conversion unit. The second converted light exits as second exiting light processed by the second and first optical unit, and the first converted light serves as third exiting light processed by the first optical unit and is combined with the first and second exiting lights to form a first beam having a first, second, and third wavelength.

Abstract: A lighting device employs at least one string of LEDs as a lighting source. The string of LEDs is coupled in series with a first switch, wherein the string of LEDs and the first switch are coupled between a power supply node and ground. During a normal operation mode, a system controller is configured to close the first switch to deliver a drive current to the string of LEDs from the power supply node. The system controller is further associated with a temperature sensor and is configured to detect an over-temperature condition based on information provided by the temperature sensor. Upon detecting the over-temperature condition, the system controller will open the first switch to stop the drive current from flowing through the string of LEDs.

Abstract: Systems and methods use cameras to provide autonomous navigation features. In one implementation, a traffic light detection system is provided for a vehicle. One or more processing devices associated with the system receive at least one image of an area forward of the vehicle via a data interface, with the area including at least one traffic lamp fixture having at least one traffic light. The processing device(s) determine, based on at least one indicator of vehicle position, whether the vehicle is in a turn lane. Also, the processing device(s) process the received image(s) to determine the status of the traffic light, including whether the traffic light includes an arrow. Further, the system may cause a system response based on the determination of the status of the traffic light, whether the traffic light includes an arrow, and whether the vehicle is in a turn lane.

Abstract: A method is provided for controlling a projection exposure apparatus for microlithography, embodied as a scanner, in the exposure operation, in which a reticle is moved along a scanning axis with respect to a frame of the projection exposure apparatus such that the reticle is scanned by an illumination field radiated thereon, and the radiation of the illumination field is guided onto a wafer after interaction with the reticle in order to generate a desired dose distribution on the wafer. The method comprises the following steps: measuring positional changes of the illumination field in the direction of the scanning axis with respect to the frame of the projection exposure apparatus, and correcting the influence of a measured positional change of the illumination field on the dose distribution on the wafer by modifying at least one operational parameter of the projection exposure apparatus.

Abstract: A resonator device 10 is disclosed. The resonator device may be used in a transducer or a sensor such as a pressure, force or acceleration sensor. The resonator device comprises a resonator 20 provided on a diaphragm 30. A cap 40 is provided which may be fusion bonded to the diaphragm 30 to enclose the resonator 20 and form a hermetically sealed package 10. The resonator device is excited by applying electromagnetic stimulation, such as infra-red or optical stimulation, which may be from a laser via a fiber 50. The resonator device may be interrogated by applying an electromagnetic signal into the optical cavity formed between the resonator 20 and the inside surface of the cap 40 to derive a frequency change of the resonator. As the resonator device incorporates a hermetically sealed package and is stimulated by electromagnetic radiation, it is robust and able to operate in harsh environments.

Abstract: A method of calibrating an image sensor may include detecting a response from a pixel of the image sensor as a result of light having an intensity impinging on the pixel, and measuring the actual standard deviation of the response of the pixel at the intensity of light. The method may also include determining an averaging number for the pixel at the intensity. The averaging number may be a number of responses of the pixel at the intensity to be averaged to attain an average response having a standard deviation less than or equal to a target value. The method may further include determining the average response of the pixel using the determined averaging number.

Abstract: A sensor unit for ascertaining control data for use in a daylight-dependent light-controlling device having an image sensor for acquiring digital image data as well as a controller for analyzing the image data and creating a brightness signal representing the daylight. The controller is designed such that when creating the brightness signal, same gives more weight to those image regions of the image data acquired by the image sensor which are more greatly influenced by the daylight.

Abstract: A lighting device that includes a lighting unit, index unit, drive unit, sensor, and control unit. The lighting unit includes a plurality of light sources, with each light source having different color spectra. The index unit is to calculate a color rendering index based on stored data on spectra of the light sources and individual first drive data for the light sources. The drive unit is to individually energize the light sources according to the first drive data. The sensor is to measure a spectral power distribution emitted by the lighting unit. The control unit is to receive the spectral power distribution, predetermined spectral power distribution, and color rendering index associated with weighted sensor values calculable from the individual first drive data, maximize the color rendering index, and stop maximization when an error between the predetermined spectral power distribution and the measured spectral power distribution falls below a limit value.

Abstract: A method for monitoring degradation of a flashlamp including triggering the flashlamp to produce a light pulse, monitoring at least one parameter as a function of time to obtain a pulse waveform of the light pulse, comparing the pulse waveform to at least one reference pulse waveform to determine a difference therebetween, and flagging an end-of-lamp-life condition when the difference exceeds a predetermined threshold.

Abstract: A method for detecting environmental illumination and a fixture built-in motion sensor thereof, comprising: obtaining the environmental lux level on visible light band through a visible light detection module and the environmental lux level on invisible light band through an invisible light detection module; the lamp is turned on when said environmental lux level of visible light is lower than the preset lux level; obtaining the mixed lux level of the lamplight and the natural light on visible light band and obtaining the mixed lux level of the lamplight and the natural light on invisible light band; calculating the turn-off threshold value for turning off the lamp through the environmental lux level and the mixed lux level. The illumination of natural spectrum is detected accurately without being interfered by the illumination of the artificial spectrum emitted by the lamp itself, thus the lamp can be controlled accurately and stably.

Abstract: A solid-state auxiliary lamp includes a lamp head having a plurality of LED modules; a thermoelectric cooler coupled to the LED modules; and a drive unit. The drive unit can include a plurality of current sources, each of the current sources coupled to a corresponding LED module; and a processor coupled to the current sources and configured to control each current source to control the light output of each current source's corresponding LED module.

Abstract: An electronic device may include a display and a light that may illuminate the display. Based at least partly on preferences of a user that is using the electronic device, a brightness of the display, and/or a brightness of the ambient environment surrounding the electronic device, the color that is being rendered by the display or that is being illuminated on the display may be determined and/or adjusted to a different color. The color may be presented or adjusted by setting or adjusting the power or current being supplied to one or more light-emitting diodes (LEDs) included within the light.

Abstract: A laser system may include a laser source configured to generate a laser light beam and an acousto-optic modulator (AOM). The AOM may include an acousto-optic medium configured to receive the laser light beam, and a phased array transducer comprising a plurality of electrodes coupled to the acousto-optic medium and configured to cause the acousto-optic medium to output a zero order laser light beam and a first order diffracted laser light beam. The system may further include a beamsplitter downstream from the AOM and configured to split a sampled laser light beam from the zero order laser light beam, a photodetector configured to receive the sampled laser light beam and generate a feedback signal associated therewith, and a radio frequency (RF) driver configured to generate an RF drive signal to the phased array transducer electrodes so that noise is diverted to the first order diffracted laser light beam based upon the feedback signal.

Abstract: In a method for visually adaptively camouflaging objects, the background and/or the surroundings in front of which and/or in which the object is situated are/is detected by means of a camera or a sensor array. The background and/or the surroundings thus detected are/is reproduced as an image (3) in a device for camouflaging the object.

Abstract: The present disclosure relates to solid state image sensors in digital imaging systems, more particularly to an image quality learning method and system for solid state image sensors. One of the advantages of the method according to an embodiment of the present disclosure is to allow the implementation of a digital machine vision system with a faster convergence of an Image Quality algorithm, which results in a shorter delay for the user. According to an embodiment of the present disclosure, the method is performed as a recursive algorithm which tends to converge to an Image Quality setting satisfying image quality criteria.

Abstract: There is provided a photoelectric switch capable of reducing a size of a whole device while suppressing light amount irregularity and color irregularity of detected light. The photoelectric switch includes: a surface mount LED, configured to generate a light containing a plurality of color components with different hues; an optical shield disposed between the surface mount LED and a light projecting lens to shield the light around an optical opening passing the light from the surface mount LED to the light projecting lens; a light receiving element configured to selectively receive the light to generate a plurality of light reception signals; a controller configured to control a light projecting amount of the surface mount LED based on the light reception signal.

Abstract: A semiconductor device includes an amplifier, a slew rate regulating circuit, a detection circuit, and a control circuit. The amplifier is configured to amplify an input signal. The slew rate regulating circuit is configured to regulate the slew rate of the input signal. The detection circuit is configured to detect the slew rate of the input signal along a signal path of the input signal between the slew rate regulating circuit and the amplifier. The control circuit is configured to control the slew rate regulating circuit based on a detection result of the detection circuit.

Abstract: A system for projecting an image, including layout information, on a surface in a building under construction has a projector mounted on a moveable support for supporting a worker at a work position in the building. The projector projects an image on a surface above the moveable support in response to an image signal defining the image to be projected. The image indicates the location of connectors, anchors, and holes to be affixed to, or cut through, the surface. A system determines the two dimensional position of the projector in the building, and a distance measuring system for determines the distance from the projector to said surface. A processor, responsive to a memory having stored building plan images, provides an image signal to the projector adjusted for the two dimensional location of the projector and for the distance from the projector to the surface.

Abstract: An apparatus comprising a light source (110), one or more light guides (104), and a light diffuser (102) having an integration chamber (114) surrounded by one or more light diffusive areas (108). The one or more light diffusive areas are configured with one or more first openings as one or more ingress areas (112) to receive light from the light source and one or more second openings as one or more egress areas (106) to provide light to the one or more light guides. For illuminating visual indicators with uniform light.

Abstract: An analyzer operable with an optical network is responsive to a probe signal reflected by a sensor in the network to convey information about targeted matter in air in the sensor. Multiple sensors at different locations in the network can be associated with respective selective optical wavelength filtering thereby enabling the analyzer to associated respective ones of the sensors.

Abstract: A proximity sensor including a housing, light emitters mounted in the housing for projecting light out of the housing along a detection plane, light detectors mounted in the housing for detecting amounts of light entering the housing along the detection plane, whereby for each emitter-detector pair (E, D), when an object is located at a target position p(E, D) in the detection plane, corresponding to the pair (E, D), then the light emitted by emitter E is scattered by the object and is expected to be maximally detected by detector D, and a processor to synchronously activate emitter-detector pairs, to read the detected amounts of light from the detectors, and to calculate a location of the object in the detection plane from the detected amounts of light, in accordance with a detection-location relationship that relates detections from emitter-detector pairs to object locations between neighboring target positions in the detection plane.

Abstract: A lighting circuit for a light source includes a drive circuit and an overcurrent protection circuit. The drive circuit supplies power to the light source. The overcurrent protection circuit is inserted between the drive circuit and the light source. The overcurrent protection circuit restricts a lamp current flowing into the light source so that the lamp current does not exceed an overcurrent threshold value. The overcurrent protection circuit includes a transistor, an inductor, a rectifier, a current sensor and an overcurrent protection controller. The current sensor generates a current detection signal according to the lamp current. The overcurrent protection controller controls ON/OFF of the transistor based on the current detection signal and the overcurrent threshold value. The transistor, the inductor and the rectifier are disposed in a T-shape.

Abstract: An apparatus including an ultrasonic motor having an electrostrictive element of a stator for driving a rotor thereof; and a microcontroller having a central processing unit (CPU), a built-in memory (ROM) and a pulse generating circuit which generates an pulse output signal which is applied to the electrostrictive element of the ultrasonic motor, wherein the pulse generating circuit comprising a rise setting register, a fall setting register, a phase adjustment data register, a cycle data register, a phase arithmetic circuit, a counter, a 1st comparator, a 2nd comparator, and a pulse generator, wherein the counter starts to count up, incrementing its count value from a count initial value, wherein the cycle data register stores, as cycle data, a count maximum value for the counter to count up to it.

Abstract: A device for the sampling of a pulsed laser beam of high energy, typically greater than 1 J, and of large size, having a diameter typically greater than 1 cm, combined with a compressor, comprises, upstream of the compressor: a sample-taking device provided with a sampling diopter capable of transmitting T % of the pulsed laser beam, T being greater than 90, and of reflecting (1?T) % of the pulsed laser beam, the reflected beam being called sampled beam, an afocal capable of reducing the size of the sampled beam, the compressor having a determined useful aperture, a device for reinjecting the reduced sampled beam into this useful aperture.

Abstract: Exemplary embodiments of the present invention disclose a display device, and a method of driving the same. The display device includes a display unit including pixels included in one or more deterioration region groups and pixels included in one or more reference groups corresponding to the deterioration region groups, a sensing unit configured to sense a current flowing through an organic light emitting diode of each of the deterioration region groups and each of the reference groups and provide current information about the deterioration region group and current information about the reference group.

Abstract: An example of a lighting system includes intelligent lighting devices, each of which includes a light source, a communication interface and a processor coupled to control the light source. In such a system, at least one of the lighting devices includes a user input sensor to detect user activity related to user inputs without requiring physical contact of the user; and at least one of the lighting devices includes an output component to provide information output to the user. One or more of the processors in the intelligent lighting devices are further configured to process user inputs detected by the user input sensor, control lighting and control output to a user via the output component so as to implement an interactive user interface for the system, for example, to facilitate user control of lighting operations of the system and/or to act as a user interface portal for other services.

Abstract: The objective of the present invention is to embody a convenient and reliable image sensor of an auto trigger scheme. The present invention provides a driving method for an image sensor in which pixels are arranged in a matrix form along row lines and column lines and which has a waiting mode and an image obtaining mode, the driving method for an image sensor comprising the steps of: when sequentially selecting a row line, applying a gate signal, and reading out a data signal for each frame in the waiting mode, calculating a variation between the data signal of the currently selected row line and the data signal of the same row line in the previous frame; and if the variation is greater than or equal to a threshold value, determining that light has been radiated.

Abstract: A three-dimensional (3D) model file, and a method and apparatus for providing the 3D model file are provided. The method may include generating a 3D model file comprising a first field defining information associated with a printing material of a 3D model to perform 3D printing, and providing the 3D model file.

Abstract: Methods and apparatus for lighting control. One or more properties of light output of one or more LEDs (124A, 124B, 124C, 124N) of an LED node (120A, 120B, 120C, 120N) of an LED-based lighting unit (110) are controlled to extend the lifetime of the LED-based lighting unit. For example, an LED node controller controlling an LED may determine whether the LED will be operated in the active light emitting state based on an LED activation probability. Thus, based on the LED activation probability the LED may at some times be in the active light emitting state and provide light output and may at other times be prevented from being in the active light emitting state and prevented from providing light output.